The advent of integrated circuitry has given rise to the need for integrated circuit packages that will both house and protect the integrated circuit die. These integrated circuit packages provide a mechanism for making electrical interconnection between the circuits on the integrated circuit die and the leads that are utilized to make electrical interconnections to circuits, power, and ground external to the integrated circuit die. In the early stages of development of integrated circuits, there were relatively few connections between the integrated circuit die and the external circuitry.
As integrated circuit packages provide electrical interconnection of integrated circuits to an electronic system at a next level of integration or hierarchy, a substrate or a carrier is one common means of electrical interconnection. Across virtually all applications, there continues to be growing demand for reducing size and increasing performance of integrated circuits.
Smaller and denser integrated circuits are required in many portable electronic products, such as cell phones, portable computers, voice recorders, etc. as well as in many larger electronic systems, such as cars, planes, industrial control systems, etc. As the demand grows for smaller electronic products with more features, manufacturers are seeking ways to reduce the size of the packaged integrated circuits. To meet these needs, packaging technologies are increasingly using smaller area designs with smaller features.
As the integrated circuit technology advanced, more circuit cells were able to be fabricated in a similar die area so that substantially increased functionality could be accomplished on a given integrated circuit die. The added functionality and increase in the number of circuits involved generally required a larger number of discrete connections to the associated external circuitry. The integrated circuit die is connected or bonded to the substrate using thin and flexible wires or bond wires.
An integrated circuit package generally includes a protective housing, which surrounds the integrated circuit die. The protective housing is usually filled with a liquid potting mixture, or other encapsulant, which then hardens in situ. During the introduction of the liquid, however, the bond wires are susceptible to mid-line motion or “sweep” potentially causing bond wires to short circuit.
A variety of approaches has been put forward to minimize or eliminate the bond wire “sweep”. The direction of the fill material entry (“center gating” and “side gating”, for example) has been varied to minimize sweep. Some attempts, such as “side gating”, with bonding patterns and systems have not provided an adequate bonding pattern to minimize shorting during fill processes. Other attempts, such as “center gating” reduces or eliminates wire “sweep” but presents other problems.
For example, the integrated circuit may be chipped or damaged by the mold gate leading to yield loss and increased cost. In another example, the “center gate” or more specifically, the top center mold gate method requires a minimum thickness at the mold gate to minimize delamination of the encapsulation. This minimum thickness constrains the reduction in the package profile.
Thus, a need still remains for an integrated circuit package system providing smaller form factor, low cost manufacturing, improved yield, and improved reliability. In view of the ever-increasing need to save costs and improve efficiencies, it is more and more critical that answers be found to these problems.
Solutions to these problems have been long sought but prior developments have not taught or suggested any solutions and, thus, solutions to these problems have long eluded those skilled in the art.